This invention relates to a washbasin drain assembly.
Design of subsystems of a commercial passenger aircraft is a continuing pursuit of a favorable balance between functionality and weight.
For several years, the lavatory washbasins in commercial passenger aircraft were generally made from stainless steel. Although stainless steel has many desirable properties with respect to this use, a basin made of stainless steel is heavier than a basin of comparable size and made of a material having a higher strength-to-weight ratio than stainless steel, such as a glass fiber reinforced synthetic polymer material.
In order to provide a basin of sufficient strength made from non-metallic material, the thickness of the basin must generally be greater than the thickness of a basin made of stainless steel.
The drain body that is connected to the outlet opening of the lavatory washbasin in a commercial passenger aircraft is connected to a waste line which supplies the gray water from the basin either to a pressure responsive valve which feeds the gray water to a drain mast for discharge from the aircraft or to a vacuum interface valve for supplying the water to a vacuum sewer through which the water is delivered to a collecting tank aboard the aircraft. In certain applications, there may be other devices downstream of the drain body.
A solid contaminant in the gray water may interfere with operation of the interface valve or other downstream device, and may lead to a flooding condition.
It is known to include a strainer in the outlet of a washbasin to prevent solid objects from entering the drain line. Depending on the installation of the basin, the purpose of the strainer may be either to protect against loss, e.g. of small items of jewelry, or to protect against blockage of the drain line, e.g. by kitchen waste. In either case, however, the strainer openings are fairly large, typically hiving a minimum linear dimension of at least 5 mm.